81028975 has 6 divisors (see below), whose sum is σ = 100475960. Its totient is φ = 64823160.

The previous prime is 81028943. The next prime is 81028991. The reversal of 81028975 is 57982018.

It is not a de Polignac number, because 81028975 - 2⁵ = 81028943 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1620555 + ... + 1620604.

Almost surely, 2^81028975 is an apocalyptic number.

81028975 is a deficient number, since it is larger than the sum of its proper divisors (19446985).

81028975 is a wasteful number, since it uses less digits than its factorization.

81028975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3241169 (or 3241164 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 81028975 is about 9001.6095782921. The cubic root of 81028975 is about 432.7264565236.

The spelling of 81028975 in words is "eighty-one million, twenty-eight thousand, nine hundred seventy-five".